52 



Mr. E. P. Perman. 



[May 8, 



vapour-density at 440 and 34'5 mm. pressure to be 106'2 (' Comptes 

 Rendus,' vol. 91, 1880, p. 54). The dissociation of iodine has thus 

 been worked oat with fair completeness, although the results of 



FIG. 2. 



Forms of Apparatus used for Iodine and Aqueous Hydrochloric Acid. (Section.) 



Deville and Troost seem very much at variance with those of other 

 experimenters. The object of my work was to discover the density 

 of iodine vapour as nearly as possible saturated. A modified form of 

 apparatus was devised by Professor Ramsay so that the iodine could 

 be conveniently introduced into the globe. The modification con- 

 sisted of the introduction of a stopper at the neck of the globe with 

 a capillary tube through the centre. The method of procedure was 

 the same as with bromine, except that it was necessary to heat the 



Temperature, 131'4 (Chlorobenzene) ; Capacity of Globe, 517'6 c.c. 





